docs(04-03): complete expense tracking plan

Tasks completed: 2/2
- Task 1: Schema + COA additions + expense category seeding
- Task 2: VendorService, ExpenseService, API routes, migration, 15 tests

SUMMARY: .planning/phases/04-inventory-expenses-and-financial-reports/04-03-SUMMARY.md

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.planning/STATE.md

@@ -10,18 +10,18 @@ See: .planning/PROJECT.md (updated 2026-03-04)
 ## Current Position
 
 Phase: 4 of 5 (Inventory, Expenses, and Financial Reports)
-Plan: 1 of 3 in phase 4 (18/20 total complete)
-Status: In progress. 04-01 (Inventory Event-Ledger) complete.
-Last activity: 2026-03-05 — Completed 04-01-PLAN.md (Inventory Event-Ledger — 13 tests, dual tracking, immutable movements, JE posting)
+Plan: 3 of 5 in phase 4 (20/22 total complete)
+Status: In progress. 04-01 and 04-03 complete.
+Last activity: 2026-03-05 — Completed 04-03-PLAN.md (Expense Tracking — 15 tests, vendor management, approval workflow, JE posting)
 
-Progress: [██████████████████░░] 90% (18/20 plans across all phases)
+Progress: [████████████████████] 91% (20/22 plans across all phases)
 
 ## Performance Metrics
 
 **Velocity:**
-- Total plans completed: 12
-- Average duration: 10 min
-- Total execution time: 120 min
+- Total plans completed: 13
+- Average duration: 11 min
+- Total execution time: 137 min
 
 **By Phase:**
 
@@ -30,11 +30,11 @@ Progress: [██████████████████░░] 90% (18
 | 01-foundation | 5/5 complete | 41 min | 8.2 min |
 | 02-subscriber-and-billing-core | 5/5 complete | 57 min | 11.4 min |
 | 03-operational-modules | 5/5 complete | ~65 min | ~13 min |
-| 04-inventory-expenses-reports | 1/3 complete | 16 min | 16 min |
+| 04-inventory-expenses-reports | 2/5 complete | 33 min | 16.5 min |
 
 **Recent Trend:**
-- Last 10 plans: 02-01 (7 min), 02-03 (7 min), 02-02 (16 min), 02-04 (12 min), 02-05 (8 min), 03-01 (15 min), 03-02 (11 min), 03-04 (6 min), 03-05 (9 min), 04-01 (16 min)
-- Trend: stable — 04-01 migration applied cleanly, all 13 tests passed on first run
+- Last 10 plans: 02-02 (16 min), 02-04 (12 min), 02-05 (8 min), 03-01 (15 min), 03-02 (11 min), 03-04 (6 min), 03-05 (9 min), 04-01 (16 min), 04-03 (17 min)
+- Trend: stable — 04-03 all 15 tests passed, migration via db push + resolve
 
 *Updated after each plan completion*
 
@@ -124,6 +124,12 @@ Recent decisions affecting current work:
 - [04-01]: CASL subject is "Inventory" (existing type in types.ts) — OFFICE_STAFF gets can("manage", "Inventory")
 - [04-01]: Stock levels derived in JS from movement aggregation — acceptable for ISP scale (same pattern as collector balances, outstanding reports)
 - [04-01]: Inventory cleanup order in tests: stockMovements -> inventoryItems -> journalEntryLines -> null reversesEntryId -> journalEntries -> accountingPeriods -> accounts -> users -> tenant
+- [04-03]: ExpensePaymentMethod determines CR account: CASH->1010, BANK_TRANSFER/CHECK->1020
+- [04-03]: Default behavior is immediate post (no approval required); requireApproval flag enables DRAFT-only creation
+- [04-03]: System expense categories (isSystemCategory=true) cannot be deleted; custom categories deletable if no expenses reference them
+- [04-03]: Vendor added as CASL subject; OFFICE_STAFF gets manage Expense and manage Vendor
+- [04-03]: ISP COA now has 31 accounts — added 5080 Fuel/Transportation, 5085 Rent Expense
+- [04-03]: Expense cleanup order: expenses -> vendors -> expenseCategories (non-system) -> journalEntryLines -> null reversesEntryId -> journalEntries -> accountingPeriods -> accounts -> ticketCategories -> expenseCategories (system) -> users -> tenant
 
 ### Pending Todos
 
@@ -141,6 +147,6 @@ None.
 
 ## Session Continuity
 
-Last session: 2026-03-05T02:32:00Z
-Stopped at: Completed 04-01-PLAN.md (Inventory Event-Ledger — 13 tests, dual tracking, immutable movements)
+Last session: 2026-03-05T02:52:00Z
+Stopped at: Completed 04-03-PLAN.md (Expense Tracking — 15 tests, vendor management, approval workflow, JE posting)
 Resume file: None